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1. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 05 Issue: 12 | Dec 2018 www.irjet.net p-ISSN: 2395-0072
© 2018, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1443
Design and Implementation of Pentagon Patch Antennas with slit for
Multiband Wireless Applications
B.Viraja1, M. Lakshmu Naidu2, Dr.B. Rama Rao3, M. Bala Krishna2
1M.Tech, Student, Dept of ECE, Aditya Institute of Technology and Management Tekkali, A.P.INDIA.
2Sr.Asst. Professor., Dept of ECE, Aditya Institute of Technology and Management Tekkali, A.P.INDIA.
3Professor, Dept of ECE, Aditya Institute of Technology and Management Tekkali, A.P.INDIA.
----------------------------------------------------------------------***---------------------------------------------------------------------
Abstract:- This paper describes the design of printed slot
antenna and prototyping on available low-cost FR-4 material
fed by a microstrip line with a pentagon slot for bandwidth
enhancement. In WIFI frequency band which are using now a
days, there are two WIFI frequency bands: Lower frequency
WIFI band at 2.4 GHz and Higher frequency WIFI band at 5.8
GHz. In this paper, a pentagon microstrip antenna with
pentagon slot is designed and analyzed its properties for WIFI
connectivity application at 2.45 and 5.8 GHz. The dielectric
material FR-4 with relative permittivity (ɛr) of 4.4 and loss
tangent (δ) 0.02 has been used as a substrate material for
designing of the proposed antenna. The thickness of substrate
material used in suggested antenna is 1.6mm. The microstrip
line feeding technique with patch insertion has been used to
feed the power to the antenna with proper impedance
matching of 50Ω so maximum power can transfer. The
pentagon microstrip antenna with pentagon slot parameters
has been analyzed in terms of return loss (dB), gain (dB) and
VSWR, etc. The Ansoft High frequency structure simulator
(HFSS) Simulation software has been usedfortheanalysisand
simulation. The proto type is fabricated and measured on
Vector network analyzer of pentagonmicrostripantennawith
pentagon slot antenna.
Key words: Lower and Higher Frequency WIFI Band;
Pentagon Microstrip Antenna with pentagon Slot; FR4;
HFSS.
1. INTRODUCTION
Now days, there is a very large demand by the end user for
integrated wireless digital at low volume and broad
bandwidth. To meet these requirements, pentagon
microstrip patch antennas are preferred. In this project,
Pentagon patch antennas are designed for multiband
applications.
There is an ever growing demand in both military and
commercial applications for antennas having the attributes
of multiband behavior. Fractal geometrics with their
complex iterative nature demonstrate these required
attributes. A Koch pentagonal fractal antenna is reported in
[1] which provides reduction in the overall size of the
antenna.
The microstrip patch antenna is a single-layer design which
consists generally of four parts (patch, ground plane,
substrate, and the feeding part). Patch antenna can be
classified as single element resonant antenna. Once the
frequency is given, everything (such as radiation pattern
input impedance, etc.) is fixed. The patch is a very thin (t<
where λo is the free space wavelength) radiating metal strip
located on one side of a thin no conducting substrate, the
ground plane is the same metal located on the other side of
the substrate [2]. The advantages of the microstripantennas
are small size, low profile, and lightweight, conformable to
planar and non planar surfaces. It demands a very little
volume of the structurewhenmounting.Theyaresimpleand
cheap to manufacture using modern printed circuit
technology. However, patch antennas have disadvantages.
The main disadvantages of the microstrip antennas are: low
efficiency, narrow bandwidth of less than 5%, low RF power
due to the small separation between the radiation patchand
the ground plane(not suitable for high-power applications)
[2].
A novel V shaped wire structured pentagonal HF antenna is
reported in [3]. The use of fractal antennas for multiband
antennas is discussed in 4,5,6]. An overview of different
shapes used for fractal antennaswerediscussedintheabove
papers. There are many other fractal geometrics that have
been found to be useful in developing antenna structures
[7,8,9].
In the work durer pentagon [10] fractal concept is
introduced in to a pentagon shaped microstrip antenna to
obtain multiband behavior and miniaturization
2. DESIGN PARAMETERS OF PENTAGON PATCH
ANTENNA
The designing of micro-strip antenna requires resonant
frequency(f0), dielectric material andheightofsubstrate(h).
The proposed antenna is designed for frequency band 5.2
GHz. The substrate used is FR-4 having dielectric constant
(∈ 𝑟) 4.34 and height (h) 1.6 mm. High dielectric constant is

2. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 05 Issue: 12 | Dec 2018 www.irjet.net p-ISSN: 2395-0072
© 2018, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1444
used for size reduction. The antenna is fed by 50 Ω micro-
strip line feed. It has a width W and length Lf. The design
formulas as given in [11] are as follows
Step 1: Calculation of the Effective dielectric
constant(€r):
Equation (1) gives the effective dielectric constant
as:
)*3.01(
2
1
hr
eff 


(1)
Step2: Calculation of the Length of Strip (Ls):
The length of the Microstrip Antenna given by the equation
(2)
effrf
c
Ls


*
*42.0
(2)
Step 3: Calculation of the Width of Ground plane(Wg):
The width of the ground plane can be calculated by the
equation (3)
effr
g
f
c
W


*
*38.1
(3)
Step 4: Calculation of the Length of Ground plane (Lg):
Here the length of the ground plane is obtained by equation
(4)
effrf
c
Lg


*
*36.0
(4)
Step 5: Calculation of the Resonant Frequency (fr):
Resonant frequency (fr) is given by the equation (5),








 3
1865212
3
LgWgLs
f
ref
r (5)
By using the Design Equations the dimensions of the patch
were calculated.
3. SIMULATION
A) Pentagon patch antenna
A pentagon patch antenna is simulated. A plane geometry of
conventional patch of radius Rp (patch radius) = 13 mm is
printed on the substrate of the dielectric material FR-4
having l×w (length × width) = 52 mm×46 mm and thickness
(h) = 1.6 mm. The dielectric constant for substrate is εr = 4.4
and has loss tangent 0.002. The antenna is excited through
microstrip feed line having dimension L (length) =25 mm
and w (width) = 2.8mm. Figure.4.1 shows the structure of
pentagon patch antenna.
Fig-1: Structure of Basic Pentagon Patch Antenna
The pentagon patch antenna is simulatedinHFSSandshown
in Figure 1. The Return loss, VSWR and Gain results are
observed.
B) Pentagon Antenna structure with Slits
The structure of this antenna is shown in Figure4.1. This
antenna is designed by using HFSS software and the
substrate used for this antenna is FR4 material of size
46*52mm.The thickness of the substrate is 1.6mm and feed
for this antenna is centre feed. This antenna is simulated at
5.8GHz frequency which is useful for WI-MAX applications.
The pentagon antenna with slot is designed by using HFSS.
The Return loss, Gain and VSWR are observedat5.8GHz.The
slit of pentagon patch has width 0.9mm, length 6.23mm and
feed length 25mm and width 2.8mm. A partial ground is
used with dimensions of 24 mm*40mm. The simulated
antenna structure is shown in Figure2.
Fig-2: Structure of Pentagon Patch Antenna with slits

3. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 05 Issue: 12 | Dec 2018 www.irjet.net p-ISSN: 2395-0072
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4. RESULTS
i) Simulation Results
A) Pentagon patch antenna
The return loss is another way ofexpressingmismatch.Itisa
logarithmic ratio measured in dB that compares the power
reflected by the antenna to the power that is fed into the
antenna from the transmission line. The simulatedresultsof
the return loss for the frequency range from 2 to 14GHz are
shown in figure.3. From return loss curve, the operating
frequencies are obtained between a bandwidth of 2 to
5.7GHz,7.14 to 10GHz and 11 to 13.2 GHz. Resonant
frequencies obtained are 2.4GHz,3.6GHz,5.6GHz and 12.8
GHz.
Fig-3: Return loss for basic pentagon patch antenna
The VSWR is basically a measureoftheimpedancemismatch
between the transmitters and antenna. The higher the
VSWR, the greater is the mismatch. The minimum VSWR
which corresponds to a perfect match is unity. The
simulation results of VSWR forthefrequencyrangefrom 2to
14 GHz is shown in figure4. The obtained VSWR is below 2
between a bandwidth of 2 to 5.7GHz, 7.14 to 10GHz and 11
to 13.2 GHz.
Fig-4 : VSWR for Basic pentagon patch antenna
Gain is nothing but the power transmitted per unit solid
angle. The 3-D gain of the pentagon patch antenna is shown
in Figure.5. Gain of any antenna should be morethan3dBfor
any applications. The Gain observed for this antenna is 4.32
dB at resonating frequency 5.6 GHz.
Fig-5: Gain of pentagon patch antenna at operating
frequency 5.6GHz
Pentagon patch antennas are simulated with different patch
side dimensions and the results are tabulated below
Table-1: Parametric Analysis of Basic Pentagon Patch
Antenna in terms of Resonating frequencies and operating
frequencies
Antenna
Patch
side
Operating
frequencies
(GHz)
Resonating
frequencies
Bandwidth
of VSWR
below2
13mm 2 to 5.7GHz
7.14to10GHz
11 to13.2GHz
2.4GHz,
3.6GHz,
5.6GHz
9GHz
12GHz
2 to 5.7GHz
7.14 to10GHz
11 to13.2GHz
Table-2: Parametric Analysis of Basic Pentagon Patch
Antenna in terms of gain
Antenna
Patch side
12mm 13mm 14mm
Gain in dB
( at 5.6GHz)
4.02 4.32 4.64

4. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 05 Issue: 12 | Dec 2018 www.irjet.net p-ISSN: 2395-0072
© 2018, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1446
B) Pentagon Antenna structure with Slits
The return loss for pentagon antenna with angular slits is
shown in Figure6.
Fig-6 : Return loss plot for Pentagon Antenna with slit
The simulated results of the return loss for the frequency
range from 2 to 14GHz are shown in figure 6.From return
loss curve, the operating frequenciesareobtained betweena
bandwidth of 2 to 5.7GHz,6.8 to 10.2GHz and 11 to 13.6GHz.
Resonant frequencies obtained are 2.4GHz,6.8GHz,9.2GHz
and 12GHz.
The simulation results ofVSWR forthefrequencyrangefrom
2 to 14 GHz is shown in figure 7. The obtained VSWR is
below 2 between a bandwidth of 2 to 5.7GHz, 6.8 to 10GHz
and 11 to 13.6 GHz.
Fig-7: VSWR plot for Pentagon Antenna with angular slits
The Gain of this antenna is 4.45dB at 5.8GHz is shown in
Figure 8.
Fig_8: Gain of pentagon patch Antenna with slits at 5.8GHz
Pentagon patch antennas with patchside13mmissimulated
with different slits dimensions (width and height) and the
results are tabulated below
Table-3: Parametric analysis of pentagon patch antenna
with patch side 13mm with slits in terms of operating and
resonating frequencies
Slit
dimensions
(in mm)
Operating
frequenci
es
Resonating
frequencies
Bandwidth
of VSWR
below2
Width=0.9
Height=6.23
2-6GHz
7.2-3.8GHz
2.4GHz,3.6GH
Z,5.8GHz,10.7
GHz
2-6GHz 7.2-
13.8GHz
Width=1,
Height=6.22
2-6GHz
9.5-14GHz
5.4GHz
11.2GHz
2-6GHz
9.5-14GHz
Width=0.8
Height=6.2
2-5.9GHz
7.2-
13.5GHz
5.12GHz
9.8GHz
2-5.9GHz
7.2-
13.5GHz
Width=0.9
Height=6
2-5.9GHz
8.5-14GHz
5.34GHz
12.1GHz
2-5.9GHz
8.5-14GHz
Width=0.9
Height=6.4
2-5.9GHz
10.4-
13.5GHz
5.6GHz
8.9GHz
2-5.9GHz
10.4-
13.5GHz

5. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 05 Issue: 12 | Dec 2018 www.irjet.net p-ISSN: 2395-0072
© 2018, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1447
ii) Fabricated antenna results
A) Fabricated Structure of Basic Pentagon antenna
Fig-9: Fabricated antenna structure
Fabricated Pentagon patch antenna is shown in Figure.9. It
has been tested by using vector network analyser (E5071C)
and observed fabricated results of return loss, VSWR of the
antenna.
Experimental setup for connecting fabricated antenna to
Vector Network Analyzer with help of SMA connector is
shown in fig 10
Fig-10: Experimental setup of Vector Network Analyzer
Fig 11 shows return loss curve of the fabricatedantenna.For
this antenna, the resonating frequencies are 2.38GHz,
5.72GHz and 8.468GHz. Return lossobservedis -32.70dBat
8.64GHz,-24.3dB at 5.72GHz and -25.48dB at
2.38GHz.Operating frequencies obtained are 2.381GHz,
5.72GHz, and 8.648GHz. Fig 12shows VSWR curve of the
fabricated antenna. The VSWR at resonating frequencies
2.38GHz, 5.72 GHz, 8.64 GHz are 1.12, 1.11 and 1.05
respectively. The bandwidth ofVSWR below2is2-6GHz,7.6-
10GHz, and 12.4-14GHz.
Fig-11: Return loss curve of fabricated pentagon antenna
Fig-12: VSWR curve of fabricated pentagon antenna
5. CONCLUSIONS
Simulated and Practical results of pentagon patch antenna
and pentagon patch antenna with slits are compared. In
order to improve the performance of antenna, slits are
introduced at edges of patch antenna
In this work, one normal pentagon shaped antennas
resonating at Resonant frequencies obtained are 2.4GHz,
5.6GHz and 12.8 GHz.were obtained by simulation. The
antenna produces four bands of frequency where as the
fabricated antenna resonating at frequencies of 2.38GHz,
5.72GHz and 8.468GHz. Return lossobservedis -32.70dBat
8.64GHz,-24.3dB at 5.72GHz and -25.48dB at 2.38GHz. The
pentagon shaped antennas with slits resonating at
frequencies obtainedare2.4GHz,6.8GHz,9.2GHzand12GHz.
The simulated results of the return loss for the frequency
range from 2 to 14GHz are shown in figure 5.2.From return
loss curve, the operating frequenciesareobtained betweena
bandwidth of 2 to 5.7GHz,6.8 to 10.2GHz and 11 to 13.6GHz.
Resonant frequencies obtained are 2.4GHz,6.8GHz,9.2GHz

6. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 05 Issue: 12 | Dec 2018 www.irjet.net p-ISSN: 2395-0072
© 2018, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1448
and 12GHz.These antennas can be used for WLAN /
Bluetooth Wi-MAX application in ISM band. It is also
observed that size reduction up to 25 % in terms of overall
size.
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